Comments

From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
GCC is very likely to read the pagetables just once and cache them in
the local stack or in a register, but it is can also decide to re-read
the pagetables. The problem is that the pagetable in those places can
change from under gcc.
With THP/hugetlbfs the pmd (and pgd for hugetlbfs giga pages) can
change under gup_fast. The pages won't be freed untill we finish
gup fast because we have irq disabled and we free these pages via
rcu callback.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
arch/powerpc/mm/gup.c | 8 ++++----
arch/powerpc/mm/hugetlbpage.c | 2 +-
2 files changed, 5 insertions(+), 5 deletions(-)